When you say excessive amount of air coming out of the exhaust, do you mean that it seems like there is just a huge flow of air coming out the tailpipe? If so, that is quite normal. Compared to a typical gas engine, the diesel engine has no throttle plate or other type of restriction in the intake, so it is sucking in (and therefore expelling) as much as air as possible, even at idle. On a typical 6.5L diesel, you can barely keep your hand over the exhaust because it is pushing so much air out. However, on a gasoline engine (at idle), there is very little air being pushed out.
I suspect that everything is normal if this is what you are referring to.
Casey
1995 K1500 Tahoe 2 door, 6.5LTD, 4L80E, NP241, 3.42's, 285/75R16 BFG K02's; 1997 506 block; Kennedy OPS harness, gauges, Quick Heat plugs, and TD-Max chip; Dtech FSD on FSD Cooler; vacuum pump deleted, HX35 turbo, Turbo Master, 3.5" Kennedy exhaust, F code intake; dual t/stats, HO water pump, Champion radiator; Racor fuel filter